How to set the custom priors config?

[GGPvsk]

Hi Wassim!
Thanks for sharing such an excellent package. I have tried to apply it in my own research, but I have 4 puzzles about the priors config.

If y(x) is as an example,
1- I hope the functions ,which are given by PhySO, contain the x**gam, and gam is a free constant. Should I add the "pow" into the "op_name=[ ......, "pow", ...... ]"? If not ,what should I do some change in the function.py?

I read the paper which you just put on the arXiv named "Class Symbolic Regression: Gotta Fit 'Em All". In the article, you say we could give the constrains on the number of occurrences of given parameters, the length of the expression and more.
2-If I want to control the number of occurrences of given parameters, should I change the arity in the Token?
3-How can I set the length of the expression?
4-As the more , could you tell more about it?

By the way, I'm really looking forward to your tutorials about the Custom symbolic optimization task in the PhySO’s documentation

I am also very looking forward your reply.

Best,
Branden